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When window functions are evaluated
Window functions and GROUP BY
Summary

Instruction

Good. As you can see, the query failed. However, let's take a look at another modification of this example:

SELECT
category_id,
MAX(final_price) AS max_final,
AVG(MAX(final_price)) OVER()
FROM auction
GROUP BY category_id;


What will happen now?

Exercise

Run the template.

As you can see, the query now succeeded because we used an aggregate function (MAX(final_price)) that was indeed available after grouping the rows. By the way, this is the only place where you can nest aggregate functions inside one another.